How Could Cultivated Meat Affect The Earth?
Cultivated meat will likely have less overall environmental impact than conventional meat.
Growing food uses about 40% of all the land on Earth, replacing natural ecosystems and causing dramatic changes to our environment.
But what environmental impacts are the most important? Scientists have identified four planetary boundaries that humans have crossed, putting the future of civilization at risk:
Food production causes most of the damage to biodiversity, forest cover, and nutrient cycles. Scientists estimate that agriculture is the source of about 25% of climate change emissions, 80% of biodiversity loss and deforestation, and 90% of nutrient pollution worldwide. Most of our food system’s environmental impacts come from raising animals. Hover over the below graphic to see how cultivated meat might compare to conventional meat in its impact on planetary boundaries.
Planetary Boundaries Model
Scientists have identified nine planetary systems that regulate life on Earth. Each of these systems has a safe and stable operating space and a boundary beyond which things can go awry. Crossing a planetary boundary means that humans are at risk for large-scale, abrupt, and potentially irreversible changes to the life-supporting systems upon which we depend. The graphic shows a snapshot of the current state of our planetary systems, including those which are most at risk.
Our Environment 101
In zone of uncertainty
Beyond zone of uncertainty
Hover over a category
on the map
* Not yet quantified
Source: Modified with permission from the Stockholm Resilience Centre
Our Environment 201
Our agricultural production practices are damaging the natural systems essential for civilization.
Scientists have identified eight natural systems that we rely on to keep civilization running:
A stable climate
Plant and animal biodiversity
A reliable water cycle
Stable nutrient cycles
Low air pollution
Healthy ozone layer
Four of these natural systems have been pushed dangerously far from their natural limits by human activity:
Climate (by greenhouse gas emissions)
Forests (by deforestation)
Biodiversity (by deforestation and other habitat loss)
Nutrient cycles (by overuse of fertilizers and overproduction of manure)
Within our food system, meat, eggs, and dairy have the biggest environmental impact.
Most of humanity’s impacts on biodiversity, forest cover, and nutrient cycles, and about a quarter of our climate change emissions, come from food and agriculture. Meat and animal products are responsible for most of the environmental damage caused by the food system, though they provide only 18% of calories and 37% of protein. At the same time, the UN Food and Agriculture Organization (FAO) expects demand for meat to increase 46% between 2012 and 2050.
Because meat is such an important and high-impact commodity, it is necessary to understand the various environmental impacts of different meat production strategies. Historically, farmers have used small numbers of livestock to convert inedible or undesirable materials (grasses, insects, food waste) into valuable and nutritious foods (meat, eggs, and dairy). Over the last century, industrialized farms have replaced traditional animal agriculture across much of the world. Industrial farms concentrate large numbers of cows, pigs, or chickens in a small space. These farms grow large animals quickly by feeding them crops like corn and soybeans. The animals, in turn, generate more manure than the farm can use. The high resource use (to grow corn and soybeans) and high rates of pollution (from manure) cause the large environmental footprint of industrial animal agriculture.
The efficiency of industrial animal agriculture comes with high environmental costs. Solutions are needed to meet the world’s growing protein demands in a more sustainable way. By growing only the parts of the animal we need, cultivated meat has the potential to provide an efficient source of protein while reducing the demand for resources and the pollution generated by the food industry.
Scientists and engineers have estimated the potential environmental impact of cultivated meat.
Even without an operating cultivated meat facility, scientists and engineers can estimate the environmental impacts by looking at the materials and processes that could be used to make it.
The growth media, scaffolding material, cultivators, and harvesting steps all have their own environmental impacts. Using a technique called “life cycle assessment,” environmental experts can add those impacts together, accounting for the effects of materials, energy, and water use throughout the supply chain, as well as pollutant emissions to air, water, and soil. These assessments can be done for any food or combination of foods (for an example, see this one on a sandwich). This lets scientists compare the impacts of very different foods, or foods produced in very different ways, like cultivated meat and conventional meat.
So far, there have been four published life cycle assessments which specifically examine the potential environmental impacts of cultivated meat.
Cultivated meat could emit fewer greenhouse gases than conventional meat.
Climate change is caused by rising levels of certain gases that prevent heat from escaping the atmosphere. Carbon dioxide, methane, and nitrous oxide are examples of these ‘greenhouse gases’ or GHGs. Because carbon dioxide (CO2) is the most common greenhouse gas, scientists usually measure GHGs in ‘CO2-equivalents,’ the amount of warming caused by all GHGs over 100 years as if they were all CO2.
Cultivated meat is not yet produced at an industrial scale, so estimates of cultivated meat’s carbon footprint are based on scientific and engineering models. Scientists expect that the GHG emissions from producing cultivated meat could be between 3 and 25 kilograms of CO2-equivalents per kilogram of meat. These estimates depend on how much energy is used to make cultivated meat and what kinds of materials are needed to feed and care for the growing cells.
Including the rest of the food supply chain (delivering cultivated meat to grocery stores and restaurants, keeping it refrigerated, and accounting for food waste), the carbon footprint of cultivated meat could be 4.6 to 29 kilograms of CO2-equivalents per kilogram of meat. For comparison, conventional meats from industrial farms in the United States emit about 28 to 210 kilograms of CO2-equivalents (beef), 8 to 13 kilograms of CO2-equivalents (pork), and 4 to 6 kilograms of CO2-equivalents (chicken) for every kilogram of meat produced. Around the world, producers of farmed seafood emit about 6 to 27 kilograms of CO2-equivalents per kilogram of fish and 8 to 52 kilograms of CO2-equivalents per kilogram of shrimp and prawns.
The carbon footprint of cultivated meat could be lower than or similar to the carbon footprints of industrially-produced conventional meat. The above data represent US production of chicken, pork, and beef, and global data for farmed fish, shrimp, and prawns. Carbon emissions will depend on the amount of energy and inputs needed to produce cultivated meat and whether the energy used comes from renewable sources. “Climate Change” by WhatIsCultivatedMeat.com can be reused under the CC BY 4.0 license.
Cultivated meat production will emit greenhouse gases for different reasons than conventional meat.
Most of the GHG emissions from conventional meat production come from fertilizer used to grow feed, manure storage, and animal digestion. (Cows burp a lot of methane - about 4 cubic feet per hamburger.) Only about 10-20% of the GHG emissions from producing conventional meat come from energy use (diesel and electricity). Scientists expect that cultivated meat production will require less fertilizer and produce no manure or digestion emissions. However, meat cultivation might use more energy than conventional meat production. A cultivated meat facility will use energy to operate machines for tasks like maintaining temperature and supplying oxygen and nutrients to growing cells. Animals use the chemical energy in their food to accomplish those tasks. This means that the sources of GHG emissions from cultivated meat will be very different from the sources from conventional meats.
Using renewable resources could drastically reduce cultivated meat’s climate impact.
Scientific models of cultivated meat production assume that the factories will use the same energy sources that we use today—mostly fossil fuels. This means that using renewable energy sources, like electricity from wind and solar, has the potential to reduce the carbon footprint of cultivated meat by more than 50%. Switching to renewable electricity sources will have a much smaller impact on the carbon footprint of conventional meats, because a smaller fraction of emissions from conventional meats come from energy use. Wind and solar energy sources won’t affect the GHG emissions from fertilizer, manure, or digestion.
Cultivated meat production could free up land to maintain forest cover and biodiversity.
Efficient land use is key to maintaining forest cover and biodiversity. Raising animals for food uses about one-third of all land on Earth. We must use our land more efficiently to feed the world’s growing population, because we need the Earth’s remaining forests and grasslands to maintain the climate, water cycle, and biodiversity. Farmers in the United States use 127 million acres of cropland to grow feed for American livestock, but only 77 million acres to grow grains, fruits and vegetables eaten by people in the US.
Meat cultivation is one of many strategies to provide more food with less land. Several studies have estimated the land-use requirements of cultivated meat at 0.5 to 5.5 square meters per kilogram of meat (m2/kg). That could involve using about 3-5 m2/kg of farmland to grow sugar and proteins, or using as little as half a square meter of land anywhere with enough sunlight to grow algae or cyanobacteria.
How does this compare to conventional meat? Industrial farms in the United States use less land to feed and raise animals than many places around the world use. But it still takes American farmers about 12 to 36 square meters of cropland to produce a kilogram of pork and 11 to 14 square meters to produce a kilogram of chicken. Raising beef cattle in US feedlots takes much more land: about 23 to 65 square meters of cropland and 40 to 300 square meters of pasture or rangeland. Even seafood can have a land use impact. Fish feed often contains grains and plant proteins. Around the world, farming fish uses about 1 to 11 square meters of cropland per kilogram of meat, and farming shrimp and prawns uses about 0.6 to 5 square meters of cropland per kilogram of edible seafood.
Cultivated meat will likely use less farmland than industrially-produced conventional meat. The above cropland use data represents conventional US production of chicken, pork, and beef, and global data for farmed fish, shrimp, and prawns. Cultivated meat and beef both have the ability to make use of lower quality land not suitable for growing crops. Beef cattle can graze on rangeland (using 39 to 310 m2/kg of meat), while cells grown for cultivated meat could be fed non-crop feedstocks like algae (using 0.5 m2/kg of meat). “Cropland Use” by WhatIsCultivatedMeat.com can be reused under the CC BY 4.0 license.
How cells are fed will determine how much land is used.
Scientists are more confident in their estimates for the land use requirements of cultivated meat than their estimates for energy use or GHG emissions. The basic principles behind farming and feeding cells are better-understood than the other technologies needed to produce cultivated meat. The range of possibilities for the land use of cultivated meat is very broad (between 0.5 and 5.5 square meters per kilogram of meat) because scientists have modeled different ways of providing nutrients to the growing cells. On the very low end, growing algae or cyanobacteria to produce sugar and protein could use very little land—less than one square meter per kilogram. Growing wheat, corn, or soybeans to feed cultivated cells might take three to five square meters per kilogram of cultivated meat.
Cultivated meat production will likely use the same amount of water as conventional meat.
When talking about water use, it is important to include the entire “water footprint” of a product. For example, in meat production, water is used to irrigate the crops fed to cows, pigs, and chickens, provided to the animals to drink, and used to clean slaughterhouses and meat packing plants.
Cultivated meat production might use water:
to irrigate the crops that are grown to “feed” the cells
to fill the tanks the cells grow in
to clean the production facility
There are three different ways that scientists and engineers can estimate a water footprint:
‘blue water’ use (all of the surface water and groundwater used along a supply chain)
‘green water’ use (all of the rainwater required to produce something)
‘grey water’ use (the amount of water needed to dilute the wastewater pollution from a farm or factory to acceptable levels).
All of these methods are valid, and each is useful in certain circumstances. Here, we are only talking about the blue water footprint of meat production: how much river water and groundwater is used to irrigate crops, supply farms and factories, and process foods.
So far, only one team of scientists has estimated the blue water use of a hypothetical cultivated meat factory. They estimate that it could take 330 to 840 liters of water to provide one kilogram of cultivated meat—about 250 liters at the factory and the rest to grow crops to feed the cells. At retail, including other stages in the food supply chain, the total water use of cultivated meat could be 360 to 920 liters per kilogram.
That sounds like a lot of water, but how does it compare to conventional meat? It takes about 490 to 20,200 liters of water to produce one kilogram of beef (L/kg) in the United States. In the US and Europe, producing conventional meat can take between 180 to 560 liters per kilogram of pork, and 220 to 1300 liters per kilogram of chicken. It also takes a lot of water to farm fish and shrimp. Some water is used to irrigate crops grown for fish feed, and to refill water that evaporates from fish and shrimp ponds. Around the world, it usually takes between 1,100 and 10,000 liters of water per kilogram to farm fish and between 660 and 4,400 liters per kilogram to grow farmed shrimp and prawns. Although there is still a lot of uncertainty in the water footprints of cultivated meat and many conventional meats, it appears that growing cultivated meat will use about as much water as conventional meat.
The water use of cultivated meat will probably be similar to industrially produced conventional meats. The above data represents water use for conventional production of chicken and pork in the US and Europe, US beef, and global production of farmed fish, shrimp, and prawns. But the environmental and human impacts of water use have more to do with where water is used than how much. Cultivated meat has the potential to reduce water use impacts if it is produced in areas with plentiful water resources. “Water Use” by WhatIsCultivatedMeat.com can be reused under the CC BY 4.0 license.
Cultivated meat will likely have a smaller nutrient pollution footprint than conventional meat.
All foods have a nutrient pollution footprint. A nutrient footprint is like the less-famous sibling of a carbon footprint or a water footprint. It’s essentially the excess nutrients from fertilizers and manure that seep into the broader ecosystem.
“Nutrients” may sound like a good thing, but when fertilizers and animal manure enter water systems, they become a serious threat to ecosystems. At the extreme, nutrient pollution causes dead zones in lakes and oceans around the world. Excess fertilizers cause algae blooms, which block sunlight, killing aquatic plants. As the plants decay, bacteria consume the oxygen that plants and animals need to survive. These dead zones, like the one at the mouth of the Mississippi River in the Gulf of Mexico, can be thousands of square miles. Most are seasonal, growing in the spring and summer as farmers in the region fertilizer their crops and shrinking in the fall.
Smaller quantities of nutrient pollution are also a problem. Fertilizer and manure runoff from farms changes the ecology of streams, rivers, and lakes, and can make water unsafe to drink for local communities.
Meat from industrial farms in the United States and other countries tends to have a high nutrient footprint for two reasons. First, cows, pigs, and chickens raised in industrial facilities consume high amounts of corn and other crops grown with fertilizer. Second, animals do not fully absorb all of the nutrients they eat, and the excess nutrients are passed along in their manure. There is far too much manure produced for the soil to absorb it or that can be used for fertilizing nearby crops. This double inefficiency—nutrient loss from growing feed crops and from excess manure—is why meat and animal products tend to have large nutrient pollution footprints.
The cells grown for cultivated meat will also need to “eat” sugars and proteins. Producers of cultivated meat may use some of the same fertilized crops used to feed animals, but scientists expect that they will need less to produce the same amount of meat. And without animals, meat cultivation won’t have the same excess manure problem as an industrial livestock farm. Because of those advantages, scientists expect that cultivated meat will have a smaller nutrient pollution footprint than meat from industrialized farms.
Only one scientific study has estimated the nutrient pollution footprint of cultivated meat production. Nutrient pollution is commonly measured using phosphate-equivalent nutrient emissions (PO4 eq), which represent the total nutrient content of phosphorus- and nitrogen-containing chemicals from a process. That study projects a footprint of 4 to 14 g PO4 eq per kilogram of cultivated meat. Accounting for the rest of the food supply chain, including food waste, gives an estimate of 6 to 17 g PO4 eq/kg for cultivated meat at retail.
For comparison, the phosphate-equivalent nutrient emissions per kilogram of meat from industrial farms in the US are between 20 and 49 grams from chicken, about 41 to 46 grams from pork, and 50 to 600 grams from producing beef. Nutrient pollution from fish and shrimp farming around the world can be quite high. Scientists estimate farming fish releases about 70 to 370 g PO4 eq/kg, while shrimp and prawn farming releases between 70 and 700 g PO4 eq/kg.
The nutrient pollution impacts of cultivated meat will probably be much lower than industrially-produced conventional meats. The above data represents the nutrient pollution conventional US chicken, pork, and beef production, and global production of farmed fish, shrimp, and prawns. “Nutrient Pollution” by WhatIsCultivatedMeat.com can be reused under the CC BY 4.0 license.